Substrate Cleaning Apparatus

This application is based on and claims priority to Korean Patent Application No. 10-2024-0081421, filed on Jun. 21, 2024, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety.

Example embodiments of the disclosure relate to a substrate cleaning apparatus.

After a chemical mechanical polishing (CMP) process is performed for a wafer (e.g., a substrate), a cleaning process may be performed to remove particles, such as residues or organic pollutants, generated on the surface of the wafer.

The cleaning process may be conducted in a manner in which a wafer enters between roll brushes, disposed above and below the wafer. A cleaning solution is sprayed on a wafer and the roll brushes are driven to rotate in a state of touching the wafer to clean the surface of the wafer.

In related art, roll brushes may have a relatively high contact rate in the middle area of the wafer than in the edge area of the wafer, and accordingly, the brush pressure is concentrated on the middle area of the wafer, which causes the wafer damage or deterioration. In addition, as porous roll brushes hold a cleaning solution, sagging occurs in the middle portion of a roll brush by a wet condition of the load, which causes the brush pressure to be further concentrated on the middle area of the wafer.

Information disclosed in this Background section has already been known to or derived by the inventors before or during the process of achieving the embodiments of the present application, or is technical information acquired in the process of achieving the embodiments. Therefore, it may contain information that does not form the prior art that is already known to the public.

One or more example embodiments provide a substrate cleaning apparatus including a brush capable of applying uniform contact pressure to a treatment target substrate.

One or more example embodiments further provide a substrate cleaning apparatus in which damage to a substrate caused by excessive contact of a brush with the substrate may be prevented while enhancing the accuracy and efficiency of substrate cleaning.

Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments.

According to an aspect of an example embodiment, a substrate cleaning apparatus may include a core including a core body extending in a length direction and configured to rotate about a central axis extending in the length direction, a plurality of magnetic members, and a brush surrounding at least a portion of the core, the brush configured to rotate together with the core and clean a surface of a substrate, where the brush includes a magnetic portion including a magnetic material, and the magnetic portion is configured to contract in a direction toward the central axis of the core body based on a magnetic force generated by the plurality of magnetic members.

According to an aspect of an example embodiment, a substrate cleaning apparatus may include a core body extending in a length direction and configured to rotate about a central axis extending in the length direction, a magnetic member in an area corresponding to a middle area of the core body based on the length direction, and a brush surrounding at least a portion of the core body, the brush configured to rotate together with the core body and clean a surface of a substrate, where the brush includes a magnetic portion configured to contract based on a magnetic force generated from the magnetic member and a cleaning portion on an outer surface of the magnetic portion and including a plurality of cleaning protrusions configured to contact the substrate, and where the magnetic member is spaced apart from the central axis of the core body in a direction perpendicular to the central axis of the core body.

According to an aspect of an example embodiment, a substrate cleaning apparatus may include a core including a core body extending in a length direction and configured to rotate about a central axis extending in the length direction, a plurality of magnetic members in the core, and a brush surrounding at least a portion of the core body, the brush configured to rotate together with the core body and clean a substrate, where the brush includes a magnetic portion included a magnetic material, and the magnetic portion surrounds an area where the plurality of magnetic members are in the core, and where the magnetic member is positioned so as to overlap the central axis of the core body.

Hereinafter, example embodiments of the disclosure will be described in detail with reference to the accompanying drawings. The same reference numerals are used for the same components in the drawings, and redundant descriptions thereof will be omitted. The embodiments described herein are example embodiments, and thus, the disclosure is not limited thereto and may be realized in various other forms.

As used herein, expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list. For example, the expression, “at least one of a, b, and c,” should be understood as including only a, only b, only c, both a and b, both a and c, both b and c, or all of a, b, and c.

It will be understood that when an element or layer is referred to as being “over,” “above,” “on,” “below,” “under,” “beneath,” “connected to” or “coupled to” another element or layer, it can be directly over, above, on, below, under, beneath, connected or coupled to the other element or layer or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly over,” “directly above,” “directly on,” “directly below,” “directly under,” “directly beneath,” “directly connected to” or “directly coupled to” another element or layer, there are no intervening elements or layers present.

In addition, expressions such as upper side, upper portion, lower side, lower portion, side surface, front surface, and rear surface hereinafter are represented based on a direction illustrated in a drawing and may be represented otherwise when the direction of a corresponding object changes. The shape or size of elements in drawings may be exaggerated for clearer description.

Hereinafter, a substrate cleaning apparatus according to example embodiments is described with reference to the appended drawings.

is a perspective view of a substrate cleaning apparatusaccording to one or more embodiments.

The substrate cleaning apparatusaccording to one or more embodiments may be configured to perform a cleaning process of removing particles, such as slurry or organic pollutants, present on the surface of a wafer (e.g., a substrate) in a semiconductor fabrication process.

Referring to, the substrate cleaning apparatusmay include one or more brush assembliesthat clean a treatment target substrate SB, and a support framethat supports the brush assemblies.

In one or more embodiments, the brush assembliesmay spray a cleaning liquid on the treatment target substrate SB and, rotate clockwise or counterclockwise about a central axis CA while contacting a surface of the treatment target substrate SB to clean the treatment target substrate SB. Various materials/solutions used for cleaning a semiconductor substrate may be applied to the cleaning liquid as will be understood by one of ordinary skill in the art from the disclosure herein.

In one or more embodiments, the substrate cleaning apparatusmay include a plurality of brush assembliesandthat are configured to clean different surfaces of the treatment target substrate SB. For example, as shown in, the substrate cleaning apparatusmay include the first brush assemblyand the second brush assemblywhich are disposed respectively above and below the treatment target substrate SB to clean an upper surface and a lower surface of the treatment target substrate SB.

For example, as shown in, the substrate cleaning apparatusmay include the first brush assemblyand the second brush assemblywhich are disposed above and below the treatment target substrate SB to clean different surfaces of the treatment target substrate SB. The first brush assemblyand the second brush assemblymay be spaced apart by a predetermined distance, and each of the brush assembliesandmay be driven to rotate and spray cleaning liquids with the treatment target substrate SB positioned therebetween and may clean opposite surfaces of the treatment target substrate SB. The substrate cleaning apparatusmay further include a substrate rotator configured to rotate the treatment target substrate SB about an axis (for example, an axis parallel with a z-axis) perpendicular to the central axis CA of the brush assembliesin a cleaning process.

In one or more embodiments, the substrate cleaning apparatusmay further include the support framesupporting the first brush assemblyand the second brush assembly. In order to adjust for the size (for example, thickness) of the treatment target substrate SB, the first brush assemblyand the second brush assemblymay be configured to be movable in a direction closer to or farther from each other on the support frameand with respect to the treatment target substrate SB. Therefore, a user may effectively clean an upper surface and a lower surface of a substrate by adjusting a distance between the first brush assemblyand the second brush assemblyin response to various sizes of substrates. However, in one or more embodiments, the substrate cleaning apparatusmay have one brush assembly or more than three brush assemblies, and an arrangement of the brush assembliesmay also be appropriately changed in response to the shape of the treatment target substrate SB.

In one or more embodiments, the brush assembliesmay be configured to partially adjust, in a length direction (y-axis direction) of the brush assemblies, the magnitude of pressure (hereinafter, referred to as contact pressure) which is applied as the brush assembliescontact the treatment target substrate SB, an area (hereinafter, referred to as contact area) in which the brush assembliescontact the treatment target substrate SB, or friction force (hereinafter, referred to as contact friction force) which is generated by such contact. For example, at least a portion of the brush assembliesmay be configured to be adjustable in thickness or volume. As the thickness or volume of at least a portion of the brush assemblieschanges, a distance between the corresponding portion of the brush assembliesand the treatment target substrate SB changes, which thus may change the contact pressure and/or the contact friction force applied to the treatment target substrate SB. This change in thickness or volume of the brush assembliesmay be implemented by a magnetic member disposed within the brush assembliesand a magnetic portion configured to adjust a thickness or volume of the brush assembliesbased on a magnetic force generated from the magnetic member.

Hereinafter, with reference to, the brush assembliesaccording to one or more embodiments including the magnetic member and the magnetic portion are described.

is an exploded perspective view of a brush assemblyincluded in a substrate cleaning apparatus according to a first example embodiment.

is a cross-sectional view of the brush assemblyaccording to one or more embodiments.

is a cross-sectional view of the brush assemblytaken along line A-A′ of, according to one or more embodiments.

is a cross-sectional view illustrating an operation of the brush assemblyofaccording to one or more embodiments.

The brush assemblyaccording to one or more embodiments illustrated infeatures the same as or similar to those described above with respect to, and thus, repeated descriptions may be omitted.

Referring to, the brush assemblymay include a coreconfigured to be rotatable about the central axis CA and a brush, surrounding at least a portion of the core. The brushmay be configured to rotate together with the coreand clean a surface of a treatment target substrate (for example, treatment target substrate SB of).

In one or more embodiments, the coremay include a core bodythat forms an overall appearance of the coreand a magnetic memberprovided on the core body.

In one or more embodiments, the core bodymay be a structure extending in one direction and may be configured to be rotatable about the central axis CA formed to be parallel with a length direction thereof (for example, y-axis direction). The core bodymay have a structure such as a circular pipe or a polygonal pipe, but embodiments are not limited thereto. For example, the core bodymay also have a structure segmented in the length direction (y-axis direction). The core bodymay have any structure in which the brushmay be supported and a frame of the brush assemblymay be stably formed.

In one or more embodiments, a flow paththrough which a cleaning liquid may flow may be disposed inside the core body. The flow pathmay extend in the length direction (y-axis direction) of the core bodyin a center portion of the core body. The cleaning liquid flowing through the flow pathmay be sprayed outward the core bodythrough a spray holein communication with the flow path.

In one or more embodiments, the brushdisposed outside the core bodymay rotate together with the core bodywhile holding the cleaning liquid sprayed from the core bodyto clean particles from a surface of the treatment target substrate SB.

In one or more embodiments, the brushmay have a material that may hold a cleaning liquid and simultaneously provide friction force sufficient to wipe particles from the surface of the treatment target substrate SB. For example, at least a portion of the brushmay have porous materials. To enhance cleaning capability, a plurality of cleaning protrusionsmay be arranged on an outer surface of the brush.

In one or more embodiments, the brush assemblymay include the magnetic membercoupled to the core bodyand a magnetic portion. The magnetic portionmay be formed as a part of the brush, or may be formed as a separate component that is provided on the core body, and on which the cleaning portionis provided. The magnet portionmay form at least a portion of the brush, and may be configured to contract based on a magnetic force generated from the magnetic memberprovided on the core body. As the magnetic portionis in at least some manner attached to the cleaning portion, when the magnetic portionis attracted by a magnetic force generated by the magnetic memberof the core body, the cleaning portionmay contract in areas corresponding to the position of the magnetic membersof the core body, reducing the contact area of the middle portion of the brushwith the treatment target substrate SB, as is described in detail below.

Referring to, the magnetic membermay be coupled to the coreand configured to generate a magnetic field around the core. For example, the magnetic membermay be formed of an electromagnet from which a magnetic field is generated when a current is applied thereto. When the magnetic memberis formed of an electromagnet, a conducting wire connected to the magnetic membermay be disposed to extend in a length direction (y-axis direction) of the corealong the inside of the core. A controllermay control the magnitude of a current applied to the magnetic memberto regulate the intensity of a magnetic field generated by the magnetic member.

In one or more embodiments, the magnetic membermay be coupled to an outer surface of the core. For example, referring to, an accommodation groovein which the magnetic membermay be accommodated may be formed on an outer surface of the core, and each magnetic membermay be accommodated in the accommodation grooveand fixed to the core.

In one or more embodiments, the magnetic membermay be disposed in a middle area of the corebased on the length direction (y-axis direction) of the core. For example, referring to, a plurality of magnetic membersmay be disposed to be spaced apart in a circumferential direction based on the central axis CA in the middle area of the core. The plurality of magnetic membersmay be disposed to be spaced apart from each other by similar distances. For example, referring toandB, four magnetic membersmay be disposed to be rotationally symmetric based on the central axis CA. By disposing the plurality of magnetic membersto be rotationally symmetric, a uniform magnetic flux line distribution may be generated around the central axis CA. However, the number or position of the magnetic membersis not limited thereto and any suitable manner for generated a magnetic field around the coremay be applied for arrangement. For example, the magnetic membersmay include three or fewer or five or more members, and distances between each other may be varied.

In one or more embodiments, the brushmay include the magnetic portionconfigured to contract by a magnetic force generated from the magnetic members. The magnetic portionmay be configured to react to a magnetic field generated from the magnetic membersby containing a magnetic material.

In one or more embodiments, the magnetic portionmay form an inner surface of the brushand be disposed to surround the magnetic members. For example, referring to, the brushmay include a stacked structure having a first layer that forms an inside surface of the brushand include the magnetic portionwith strong magnetism and a second layer that forms an outside surface of the brushand include a material without magnetism (or with very weak magnetism). The second layer may be a portion that directly contacts the treatment target substrate SB and may be configured to hold a cleaning liquid and clean a substrate. In The second layer portion that forms the outside surface of the brushis referred to as a cleaning portion.

In one or more embodiments, the magnetic portionmay surround at least a portion of the outer surface of the coreand may be disposed to surround an area where the magnetic membersare disposed in the core. Whileshow the magnetic portionextending the entire length of the coreand the cleaning portion, embodiments are not limited thereto, and the magnetic portionmay have a smaller extension length as described below.

In one or more embodiments, the magnetic portionmay be configured to contract when a magnetic force is applied from the magnetic members, decreasing the thickness or volume of the brush assembly at areas corresponding to the magnetic members. The magnetic portionmay be configured to thereafter expand back such that the brush assembly reverts to its original thickness when the magnetic force is removed. To this end, the magnetic portionmay be configured to have both magnetism and elasticity.

For example, the magnetic portionmay be formed of a magnetic polymer that has magnetism itself and may contract in volume or thickness elastically by external force. In this case, the magnetic polymer may include a PANICNQ polymer which is a combination of emeraldine-based polyaniline (PANi) and tetracyanoquinodimethane (TCNQ). In addition, the magnetic portionmay also include a material in which a polymer substance without magnetism (or with very weak magnetism) such as polyvinyl acetate (PVA), polyurethane, and polyamide doped with a magnetic particle having strong magnetism. For example, the magnetic particle may be a metal particle including at least one of iron (Fe), chromium (Cr), nickel (Ni), cobalt (Co), and manganese (Mn). For example, the magnetic particle may include ferromagnetic particles such as Fe2O3, CoFe2O4, FeOFe2O3, NiOFe2O3, CuOFe2O3, MgOFe2O3, MnBi, MnSb, MnOFe2O3, Y3Fe5O12, CrO2, MnAs, and EuO. Alternatively, the magnetic portionmay include a material in which a magnetic polymer substance is mixed with a magnetic particle. In contrast, the cleaning portionforming the second layer of the brushmay include a polymer material without magnetism (or with very weak magnetism) such as polyvinyl acetate (PVA), polyurethane, and polyamide.

In one or more embodiments, the magnetic portionconfigured to have strong magnetism, elasticity, and contractility may contract in volume by a magnetic force applied from the magnetic members. As the volume of the magnetic portioncontracts, the thickness of an area where the magnetic portionis disposed in the brushmay decrease corresponding to a contracted volume of the magnetic portion. For example, referring to, as a magnetic field is generated from the magnetic members, the thickness of the magnetic portionnear the magnetic membersmay decrease locally. In other words, as magnetic attraction of the magnetic membersis applied to the magnetic portionnear the magnetic members, a corresponding area of the magnetic portionmay contract in a radius direction (or a direction perpendicular to the central axis CA) of the core body. As the thickness of the magnetic portiondecreases locally, the thickness of a corresponding area of the brushdecreases locally, which increases a distance between this area of the brush assemblyand the treatment target substrate SB, which in turn may decrease the magnitude of the contact pressure or the contact friction force which the brush assemblyapplies to the treatment target substrate SB.

For example, when a cleaning process is conducted as the brush assembliesand the treatment target substrate SB are disposed horizontally as shown in, an edge area of the treatment target substrate SB comes into contact with the brush assemblyat regular time intervals according to a rotation cycle of the treatment target substrate SB, but a middle area of the treatment target substrate SB maintains a relatively constant state of contact with the brush assembly. As such, excessive contact between the brush assemblywith the treatment target substrate SB at the middle of the treatment target substrate SB) may occur (i.e., higher duration of contact and/or greater contact force). In order to prevent the treatment target substrate SB from damage by the excessive contact, the contact pressure or the contact friction force which the brush assemblyapplies to the middle area of the treatment target substrate SB may be suitably changed. In the brush assemblyaccording to one or more embodiments, the magnetic portionmay contract based on a magnetic force generated from the magnetic members, thus decreasing the thickness or volume of a portion corresponding to the middle area of the treatment target substrate SB in the brush. Accordingly, since the contact pressure or the contact friction force which the brush assemblyapplies to the middle area of the treatment target substrate SB is decreased, the damage to the treatment target substrate SB by excessive contact with a brush may be prevented.

Further, in the brush assemblyaccording to one or more embodiments the thickness of a middle area of the brushmay decrease and the middle area of the brushmay be prevented from sagging that may be caused in a wet condition due to a cleaning solution (i.e., the weight of the cleaning solution in the cleaning protrusions may cause sagging). This may allow an entire area of the brush assemblyto apply the contact pressure to the treatment target substrate SB at a substantially constant level. Accordingly, a cleaning capability of a substrate cleaning apparatus (for example, 1 of) may be maximized and fault occurrence in a treatment target substrate may be reduced.

The contraction of the magnetic portionmay be controlled through the controller. For example, the magnetic portionmay decrease in thickness or volume corresponding to the magnitude of a magnetic force generated from the magnetic members, and the controllermay variably regulate the thickness of the brush assemblyby regulating the magnitude of a current applied to the magnetic members. When the magnitude of the magnetic force generated from the magnetic membersincreases, a contracted volume of the magnetic portionmay increase and a thickness of the brushmay decrease in response thereto. Conversely, when the magnitude of the magnetic force generated from the magnetic membersdecreases, a contracted volume of the magnetic portionmay increase and a thickness of the brushmay decrease in response thereto. Thus, the controllermay change the magnitude of the contact pressure or the contact friction force which the brush assemblyapplies to the treatment target substrate SB by regulating the intensity of the magnetic force generated from the magnetic members.